Cold, tired, irritable? Well you're in good company here. A lot of us face this every day. If you live in the North, or in a cloudy area, it's especially common at this time of year. Seasonal depression causes all those symptoms, and sometimes makes you want to eat more carbs and sleep longer.

If you're always colder than other women you know (men are usually warmer so don't compare yourself to them), then you should get your thyroid function checked out.

It could really be a LOT of things. The most obvious cause is lack of sleep, by choice, or due to insomnia, sleep apnea, too much caffeine or alcohol, etc. Other causes: Depression (very common in women), poor nutrition, lack of physical activity, iron deficiency, hormonal fluctuations (PMS, perimenopause), or some run of the mill illness (virus, allergies, digestive problems) that is making you feel run down.

If you're not already taking vitamins, try a multi-vitamin, with folic acid, iron, and extra B vitamins for a week to see if you feel better. Exercise can really help make you feel warmer and more energetic, and reduce the stress hormones that can cause irritability and more serious health problems.

If you drink a lot of coffee during the day, that could actually make you feel MORE tired, because it's dehydrating and can interfere with sleep at night. Alternate with water to make sure you're getting enough real hydration. Alcohol also interferes with the quality of your sleep. If you're eating a lot of sugar or carbs, it could cause blood sugar fluctuations that make you feel tired and irritable. Eat protein and fiber with every meal to keep your blood sugar more stable.

If you think it's seasonal depression, try to get some bright sunlight early every day. Exercise is also helpful in fighting all kinds of depression, partly because it raises your body temperature. It's proven to be as effective in treating depression as antidepressants.